Coking of hydrocarbon oils



Feb. 4,' 1936.. A MEKLER 2,029,783

COKING OF HYDROCARBON OILS Filed Deo. 2s, 1931 /l/ 3 C9 F 'j OL Bgm/Ef?J5 8 J Z .9 BURNR Z 4 2j y J0 7 y ./1 2 Z olL [9 14; O 8.2112211222211112222222Z; *OIL T\\ le vr-C' ,9

QuE/VCH! G AND SEALING Llama Z'wAr/so/rs-rsnn JVAPOROUTLET fafa?.)Zeitler f Patented Feb. 4, 1936 UNITED -STATES lPATENTy OFFICE r2,029,783 COKING F HYDROCABBON OILS Lev A. 'Mekler, Chicago, lll.,assignor to Universal Oil Products Company, Chicago, Ill., a corporationof South Dakota Y Application December 28, 1931, Serial No. 583,597

' sclaims. (ol. 2oz-5) This invention relates to the treatment ofhydrocarbon oils, and more particularly refers to an improved processfor the continuous coking or carbonization of relatively heavy oils.

'I'he present invention provides an improved process for the continuousproduction of petroleumcoke of a relatively low volatile content'.

Aside from the continuity of operation provided by the presentinvention, some of the additional advantages are:

An improved method and means of heating the material undergoing cokingor carbonization whereby radiant heat is supplied directly to the massof material being treated, at the Sametime keeping said material out ofcontact with com` -bustion products, and thereby permitting thecollection of hydrocarbon vapors evolved duringrv permitting the removaland collection of the.

carbonaceous products in relatively large lumps,

minimizing the .formation of iines and obviating the necessity ofbriquetting the fuel.

An improved method and means by which a layer of coke of increasingdimensions is progressively built up upona moving surface, the freshmaterial supplied to said 'layer being that exposed to highesttemperatures, which permits the production of a product ofsubstantiallyuniform structure throughout its mass as compared with carbonaceousproducts of other processes.

The invention also provides for the additional carbonizing or baking ofthe coke or carbonaceous materiah when so desired, after its removal'from the primary coking zone.

The novelties and features of the present invention will be moreapparent with reference to the accompanying diagrammatic'drawing,illustrating one specic form of apparatus embodying the principles ofthe invention, and from the following description of the drawing.

Fig. 1 is a cross-sectional side elevation of the coking apparatus, and

Referring more in detail to the drawing, a cylindrical shell I supportedo n a hollow central shaft 2 is located within furnace 3 and isseparated from the combustion zone I of the furnace by means cfa muiiie`5, which ispreferably constructed of suitable material of relativelyhigh heat conductivity, such as silicon carbide, fused or molded silica,fused or molded alumina, or the like. Any suitable motivating means (notshown) is provided for rotating the coking shell I through a gearingarrangement, for example, such as that indicated at 6.

Combustible materials are supplied to the combustion zone I of furnace 3through vany suitable burner or burners indicated at 1, additional heatbeing supplied within the upper portion of the combustion zone, if .sodesired, by means of an additional burner or burners 1. 'I'he walls ofmuliie 5 assume a degree of incandescence upon heating, permitting thetransmission of radiant heat through said walls to the outer surface ofshell I, and more particularly, to the materials sprayed upon thisshell, as will be later more fully described. l

Suitable spraying devices, such as indicated at 8, 8', 8" and 8', permitthe introduction of oil to be coked into the coking and carbonizingzone, and introducing it preferably in the form of a spray onto theoutside surface of the coking shell I at progressive points around itscircumi ference. The spraying devices are preferably jacketed and cooledwith water or steam, particularly at the points where they extendthrough combustion zone 4, and in addition they are preferably protectedfrom the ame and hot combustion products in this zone by suitablerefractory sleeves 9. v

Suitable sprays I0 are provided, as illustrated, through which .acooling medium, such as water or steam,.may be sprayed onto the surfaceof a carbonaceous material upon shell I at a point in the -travel ofshell I such as indicated approximately at I I. Cooling of the layer ofcarbonaceous material upon the surface of shell I in the mannerdescribed causes it to contract and crack, sheering away from thesurface of the shell, to be caught upon the inclined plane I2 anddischarged from the colnng chamber I3.

A series of chain doors I4 permit the passage of coke or carbonaceousmaterial from the coking zone but substantially prevent or retard theegress of hydrocarbon vapors from this :que as well as the ingress ofcombustion products to this zone.

Hydrocarbon vapors evolved during the coking operation in chamber I3 maybe removed therefrom through hollow central shaft 2, gaining access tothe interior of this shaft through perforations I5 and passing through asuitable stationary vapor line I6 to any desired further treatment.Ports I1 in the lower portion of coking zone I3 Apermit the removal ofany carbonaceous material that may collect upon the iioor of muiile 5.Accumulations of coke upon the inner surfaces of the walls of muilie 5may be removed by the introduction of air, by well known means (notshown), 'to the coking zone during which time the supply of oil to thiszone is preferably discontinued, vaporsand gases being wasted during thecoke removing operation.

The coke or carbonaceous material from coking zone I3 may be the finalproduct of the system, or it may, if desired, be subjected to furtherheat treatment in furnace I8. In the latter case, coke is dischargedfrom coking chamber I3 onto a suitable conveyor I9,'preferably of chaingrate or similar construction, and preferably constructed of a suitablehigh temperature metallic alloy. Combustion products from combustionzone 4 of furnace 3.pass through ducts 20 into furnace I8 and, ifdesired, additional heat may be supplied to this zone by means of fuelintroduced through a suitable burner or burners 2|. Combustion productspreferably pass downward through the bed of coke undergoing treatment onconveyor I9 and are removed from furnace I8 together with hydrocarbonvapors evolved during their baking operation through ducts 22 to a stack(not shown) or to suitable scrubbing means (not shown) for the removalof hydrocarbons. Preferably, however, suillcient air is supplied tofurnace I8 to permit the substantial combustion of any hydrocarbonvapors evolved in this zone. The nished carbonaceous materials fromfurnace I8 may pass through port 23 onto a conveyor 24 of any suitableform which is preferably immersed in water or other suitable liquidmedium contained within sealing arrangement 25, serving to quench thecoke and also sealing furnace I8 to prevent ingress of air at thispoint.

As a specific example of the operation of the process of the presentinvention, a residual oil resulting from cracking having a specificgravity of approximately 0.98 and a coke content by laboratory analysisof approximately 30% is the material to be treated. The coking cylinderis slowly rotated in counter clockwise direction and, prior to startingthe feed of oil to the system, the coking cylinder is heated to atemperature of about 1,000 F. A portion of the oil is then sprayed ontothe outer surface of the cylinder through .the spray most adjacent tothe oor of the furnace and additional quantities of the oil are sprayedon top of the resulting carbonaceous material at progressive pointsaround the circumference of the coking cylinder during its rotation. Thespeed of rotation of the cylinder is regulated to permit substantialcoking. of each spray of oil prior to the spraying of additional oilonto the surface of the latter. Firing of the furnace is so controlledthat a substantially uniform temperature of about `1000 F. is maintainedaround the entire circumference of that portion of the cylinder to whichcarbonaceous material adheres. The introduction of small quantities ofwater through the spray provided at the outlet from the coking zonecools the carbonaceous mass sufiiciently to effect its removal from thecylinder, the coke being cooled, for example, to a tempera- Y ture ofapproximately 700 F. The coke is subsequently heated during its passageupon the 5 conveyor through the secondary heating zone to a temperatureof about 1,000 F., the speed of the conveyor being regulated to maintainthe coke at substantially this temperature for approximately 20 minutes.

An operation such as outlined may yield a total liquid and coke recoveryof approximately 75% of the charging stock, the remainder beingchargeable to uncondensable gas and loss. 'I'he liquid products maycomprise, for example, about 15 15% of motor fuels having a highantiknock value, about 5% of heavy tars, and about 30% of intermediateproducts suitable, for example, as cracking stock. The coke produced hasa volatile content of'about 8% and is recovered in 20 substantially lumpform suitable for use as fuel without briquetting.

I claim as myinvention: 1. A process for coking heavy hydrocarbon oils,which comprises continuously discharging the 26 oil onto the exteriorsurface of a cylinder rotating within a heating zone, the oil beingsprayed onto the surface at spaced points in the path of rotation of thecylinder, generating a coking heat in the heating zone exteriorly ofsaid cylinder 30 and transmitting the same directly to the oildischarged onto the cylinder, regulating the speed of rotation of thecylinder to effect substantial coking of each spray of oil between thepoint of discharge thereof onto said surface and 35 the Ypoint ofdischarge of the next succeeding oil spray onto the surface, andremoving the coke from the exterior surface of the cylinder.

2. A process for coking heavy hydrocarbon oils, which comprisesdischarging the oil onto the exterior surfacey of a cylinder rotatingwithin a heating zone, generating a coking heat in the heating zoneexteriorly of said cylinder and transmitting the same directly to theoil discharged onto the cylinder, continuing the discharge of oil ontothe cylinder until a substantial quantity of the coke has formedthereon, and removing the coke from the exterior surface of thecylinder, by spraying a cooling medium onto a portion of the coke layeraccumulated on the cylinder.

3. A process for coking heavy hydrocarbon oils, which comprisesdischarging the oil onto the exterior surface of a cylinder rotatingWithin a heating zone, generating a coking heat in the heating zoneexteriorly of said cylinder and transmitting the same directly to theoil discharged onto the cylinder, continuing the discharge of oil ontothe cylinder until a substantial quantity of the coke has formedthereon, and removing the coke from the exterior surface of a portion ofthe coke layer accumulated on the cylinder, and then conveying the cokethrough a second heating zone and drying the same therein.

4. A coke producing process, which comprises discharging heavyhydrocarbon oil onto a continuously moving surface in a radiant heatzone, the oil being sprayed into said zone and onto said surface at aplurality of spaced points in the path of travel of the surfaceburningfuel in said zone out of contact with the moving surface and developinga region of radiant heat adjacent substantially the entire portion ofsaid surface, cok- 75 ing the oil `on said surface by the radiant heatthus developed; regulating the speed of travel of said surface to effectsubstantial coking of each spray of oil between the point of dischargethereof onto the surface andthe point of discharge of the nextsucceeding oil spray onto the surface, each succeeding spray beingapplied to a previously coked layer whereby a plurality of layers ofcoke are formed, and removing the coke from the moving surface.

5. A coke producing processLwhich comprises discharging heavyhydrocarbon oil onto a continuously moving surfacein a heating zone inlwhich is disposed a stationary heat radiating surface substantiallycoextensive with the area of moving surface in the heating zone, the oil'being sprayed into said zone and onto the. moving surface at spacedpoints in the path of travel of the moving surface. maintaining saidstationary sur` face at a coking temperature, radiating a coking heatdirectly from the stationary surface to the oil on the moving surface,regulating the speed of travel of the moving surface to effectsubstantial coking of each spray of oil between the point of dischargethereof onto the moving surface surface.

LEV A. MEKIER.

